The studies on thermodynamics of irreversible processes currently concentrated on dissipation structure. While the most chemical reactions cant come to dissipation structure no matter how far the system from equilibrium. The chemical reaction rate ordinarily cant be described through a uniform equation at the same time. Here we describe the use of thermodynamics of irreversible processes theory to constitute the kinetic equation of homogeneous single chemical reacting system far from equilibrium. We find that when the equation is applied to the water-gas reaction, the equations of the fifth-order expression are obtained. Our results show that thermodynamics of irreversible process can be applied to chemical reacting systems which are far from equilibrium after the high-order term are considered.